Regulating downhole pressures in an oil and gas well is often required to set pressure actuated downhole tools, such as packers and bridge plugs, and for performing hydraulic formation fracturing, well logging, and other known operations that can be associated with well drilling, well completion, and/or well production. Hydraulic packers, for example, can be actuated by applying pressure through the borehole tubing to the packer. However, the tubing below the packer must be plugged to build sufficient pressure to set the packers. A two-way barrier is often used to hold the pressure from below for well control and hold the pressure from above for fluid loss control or setting packers. Normally a plug is run on slickline, wireline, coiled tubing, or pipe and set below the packer to act as the two-way barrier. After setting the packer and any other operations requiring the two-way barrier, the plug is retrieved to clear the flow path.
Pressure actuated devices, such as formation isolation valves, sliding sleeves, and circulating valves, generally use shear pins or metal rupture discs to block the downhole pressure from inadvertently operating the downhole device. An intervention operation, such as the application of a shear force that is generated at the surface and translated through the wellbore via the work string, is typically used to rupture the disc or shear the pins in order to actuate the devices. In some environments, however, such as an open hole, sufficient pressure cannot be obtained to provide the shear force needed to rupture the disc or shear the pins. There is also a risk of not being able to successfully remove the pressure actuated device when no longer need, which may require a milling operation to remove instead.
There is a need, therefore, for new apparatus and systems that can decrease or eliminate the necessity for intervention and/or milling operations, thereby save valuable rig time, increase operational flexibility, and minimize milling operations or other interventions.